A panel of B.C. Court of Appeal judges has been mulling B.C.’s constitutional reference case that asks whether it can create a permit regime for companies that want to increase the flow of heavy oil through the province.

B.C. argues the proposed law is aimed at protecting its lands, rivers and lakes from a hazardous substance, but Alberta and the federal government say the goal is to delay or block the expansion of the Trans Mountain pipeline.

The Trudeau government has purchased the pipeline and expansion project for $4.5 billion and Alberta sees it as an essential development to revitalize its sagging energy sector.